flex fuel problems

[vasfras@windstream.net]

Have 1999 flex fuel ranger. Installed new pump, there were 2 items above pump 1 a pulse dampener and 2 ??????? I do not know, Still have only 55lbs on rail but it drops off at 2500 rpm. checked damper on right rail and ok. No codes and exhaust is clear. in line filter was replaced 100miles ago. does the in line flex senser have any to drop pressure???? open for ideas. Thanks

 

[RonD]

What brand of pump did you use as replacement and what was the original problem that lead to replacement?
Did you replace the whole assembly in the tank or just the pump?

And have you checked voltage at battery and at fuel pump?
Engine off battery voltage should be 12.3 to 12.8volts DC

Engine running battery voltage should be 13.6volts
It will go up to 14.5v to 14.9v just after starting but drop down to 13.6volts after a few minutes

Voltage at the pump should be the same as battery voltage, engine off or engine on.


Since you have a pressure gauge, does the pressure hold after engine is shut off, it should hold pressure for a few months not a few minutes.
Cycle key on then off 3 or 4 times to see if pressure gets up to 65-70psi, fuel pump runs for 2 seconds each time key is turned on.
Then see if that pressure holds, engine off.
If pressure doesn't get up to 65psi then problem is in the pump, and if pressure doesn't hold then problem is in the check valve in the pump assembly.

If pressure does get up to 65psi and holds but drops to 55psi and even less with engine running then you have a flow problem.
Could be fuel pump but could also be new fuel filter, remember "new" no longer means "it works"
"New" now means "never tested, but we warranty it", lol

Never ran across a Flex fuel sensor that restricted flow, or read about one that did that, you could be the first but it would be long odds on that being the problem.

 

[vasfras@windstream.net]

flex fuel pressure

replaced pump only. Reading other reviews it stated in 1999 ford went a non return system , but this one has 2 lines to it and it appears that there is a vac. opperated regulator on the fender well. also as in non return systems it has a pressure regulator above the pump, which I did know what it was. My next test is to see what the pressure is at the filter to what is coming of the tank.

 

[RonD]

Have a read here: http://www.ranger-forums.com/2-9l-3-0l-v6-tech-32/key-engine-running-fuel-pressure-103627/

Looks like your pressure is OK, the fact it is dropping above 2,000rpm, I assume, is the issue